Device and method for inspecting bottles or similar containers

Abstract

A container inspection device includes at least two cameras displaced from each other in a container's direction of travel and camera axes perpendicular to that direction. Each camera records an image of the same container region when the container is directly in front it. A difference between the images indicates a defect in form of the container. A device moves the container and records these images by some combination of rotating and/or pivoting. An electronic evaluation system compares the images and ascertains a defect in the form of the inspected container if they are different.

The invention claimed is: 
     
       1. An apparatus for inspecting containers, said containers, in absence of a defect in form, being at least one of rotationally symmetric to one of a rotational axis of said container and a pivotal axis of said container, said apparatus comprising a transport path for said containers along a direction of transport, said direction of transport and said rotational axis of said container defining a plane, a camera system for recording at least two images of a region of a container, said camera system comprising a first camera having a first camera axis that is perpendicular to said plane, and a second camera having a second camera axis that is perpendicular to said plane, said second camera being displaced from said first camera in said direction of transport, wherein said first camera is configured to record a first image, said first image being an image of a region of said container at an intersection of said plane and said first camera axis when said container is in front of said first camera, and wherein said second camera is configured to record a second image, said second image being an image of said region of said container at an intersection of said plane and said second camera axis when said container is in front of said second camera, whereby a difference between said first image and said second image is indicative of a defect in form of said container, a device for moving said container between recording of said first image and recording of said second image, wherein moving said container comprises at least one of rotating said container about said rotational axis and pivoting said container about said pivotal axis between recordation of said first image and said second image, and an electronic evaluation system for evaluating said first image and said second image, wherein said electronic evaluation system is configured for comparing said first image and said second image, and ascertaining a defect in form in said inspected container if said first image and said second image of said region of said container differ from one another. 
     
     
       2. The apparatus of  claim 1 , wherein said transport path advances said containers in front of said camera system along said direction of transport. 
     
     
       3. The apparatus of  claim 1 , wherein said cameras comprise at least one CCD camera. 
     
     
       4. The apparatus of  claim 1 , further comprising a control device for controlling said camera system in such a manner that said first image of said region is recorded at a first position of said container relative to said rotational axis and said second image of said is recorded at a second position of said container relative to said rotational axis, whereby in the absence of a defect in form, said first image would be identical to said second image and in the presence of a defect in form said second image would differ from said first image. 
     
     
       5. The apparatus of  claim 1 , wherein said camera system comprises at least a first group of cameras and a second group of cameras, wherein said first group of cameras comprises a first and second camera and said second group of cameras comprises a third and fourth camera, and wherein said first camera records said first image, said second camera record said first image, said third camera records said second image, and said fourth camera records said second image. 
     
     
       6. The apparatus of  claim 1 , wherein said device for moving said container between recording of said first image and recording of said second image comprises a first support surface for said container and a second support surface for said container, said first support surface being formed by a continuous revolving belt that can be driven at a first velocity, and said second support surface being formed by a continuous revolving belt that can be driven at a second velocity, wherein said second velocity is greater than said first velocity. 
     
     
       7. The apparatus of  claim 1 , wherein said device for moving said container between recording of said first image and recording of said second image comprises a rotating container carrier for a hanging configuration of said containers, wherein said rotating container carrier can be moved in a direction of transport. 
     
     
       8. The apparatus of  claim 1 , wherein said device for moving said container between recording of said first image and recording of said second image comprises a rotating container carrier for a standing configuration of said containers, wherein said rotating container carrier can be moved in a direction of transport. 
     
     
       9. The apparatus of  claim 1 , wherein said device for moving said container between recording of said first image and recording of said second image comprises a pivoting container carrier for a hanging configuration of said containers, wherein said pivoting container carrier can be moved in a direction of transport. 
     
     
       10. The apparatus of  claim 1 , wherein said device for moving said container between recording of said first image and recording of said second image comprises a pivoting container carrier for a standing configuration of said containers, wherein said pivoting container carrier can be moved in a direction of transport. 
     
     
       11. A method for inspecting containers for defects in form, said containers, in the absence of a defect in form, being rotationally symmetric about one of a rotational axis and a pivotal axis, said method comprising moving a container along a direction of transport, providing a camera system having a first camera, and a second camera offset from said first camera along said direction of transport, said first camera having a first camera axis perpendicular to a plane defined by said direction of transport and said rotational axis of said container, and said second camera having a second camera axis perpendicular to said plane, creating a first image of a region of said container when said container is in front of said first camera and said first camera axis intersects said region, moving said container after creating said first image, wherein moving comprises at least one of rotating said container about said rotational axis and pivoting said container about said pivotal axis, after having moved said container, creating a second image of said region of said container when said container is in front of said second camera and said second camera axis intersects said region, comparing said first image and said second image, and registering a defect in form in said container when said first image and said second image are different. 
     
     
       12. The method of  claim 11 , further comprising controlling said camera system in such a manner that said first image is recorded at a first position of said container relative to said rotational axis, and said second image is recorded at a second position of said container relative to said rotational axis, whereby in the absence of a defect in form, said first image and said second image would be identical and when a defect in form is present, said first image would differ from said second image.